Polymeric-Based Theranostic Nanocarriers of Neuroprotective Drugs: Development, Imaging, and Bioanalysis.

Inefficient delivery of neuroprotective drugs to their target sites remains a major impediment in the treatment of neurodegenerative disorders. Therefore, our research was focused on a new strategy for the preparation of polymeric-based theranostic nanocarriers of neuroprotective drugs. Polymeric theranostic nanocarriers of calcineurin inhibitors, Cyclosporin A (CsA) and Tacrolimus (FK506), as potential neuroprotective agents, were prepared via the self-emulsification solvent evaporation (SESE) method with the combination of a layer-by-layer technique. For magnetic resonance imaging, gadolinium-labeled poly-l-lysine (PLL-Gd) was used, while for optical imaging, rhodamine-labeled poly-l-lysine (PLL-ROD) was used. Developed nanocarriers were characterized for their properties: the size was below 250 nm, the encapsulation efficiency was ∼100%, and they could serve as transport devices for therapeutic cargo and imaging compounds, e.g., distribution assessment. Developed nanocarriers were safe for tested cells (human neuroblastoma cells, primary neuronal cell cultures, and brain microvascular endothelial cells). Equally important, they willingly traversed the artificial blood-brain barrier. Our study demonstrated that the newly designed polymeric-based theranostic nanocarriers possess favorable physicochemical and biological properties and may serve as a useful platform for neuroprotective compound delivery.